Question

Which of the following gases would be the most and least ideal at 298 K and 1 atm. Explain.

Carbon monoxide gas, carbon dioxide gas, neon gas, ammonia vapor

Answer 1

We know that 1 mole of an ideal gas occupies a volume of 22.4 dm³.

Therefore if we know the densities of the gases at the given temperature and pressure, we can easily calculate the molar volume occupied by each of the gases.

Gas	Density (gm/dm3)	Molar mass (gm/mol)	Molar volume (Molar mass/density)
CO2	1.842	44.01	23.89
CO	1.165	28.01	24.04
Ne	0.899	20.18	22.44
NH3	0.717	17.03	23.75

As we can clearly observe from the above table, the Molar volume of Neon is closest to the expected ideal gas value, followed by NH₃ and then by CO₂ and finally CO.

The stability goes as Ne>NH₃>CO₂>CO.